Manchester United are confident of sealing Luke Shaw's signature with a new bid of £30m. Photograph: Steven Paston/Action Images

Manchester United are set to return with an improved bid in the region of £30m for Southampton's Luke Shaw once Louis van Gaal is formally announced as their new manager. The club hope to do this no later than Thursday.

United had a bid of £27m rejected earlier this week by Southampton, with the south-coast club insistent the 18-year-old is not for sale. However, United are convinced the transfer of the left-back is nearing completion and the higher offer will test Southampton's resolve.

As reported by the Guardian, United will make Shaw the highest-paid teenager in domestic football history by offering him a £100,000 a-week salary over five years, with the just deposed champions set to beat interest from Chelsea and Manchester City for the player's signature.